Carbon black is generally produced by pyrolytic decomposition of hydrocarbons. A carbon black containing smoke is generated. The carbon black is separated from the smoke, e.g., by filtration. Thus a flocculent carbon black product is obtained. This flocculent carbon black product is difficult to handle. Thus it is common practice to convert the flocculent carbon black into pellets.
Various carbon black pelleters have been disclosed in the prior art. One such pelleter comprises a housing with two parallel rotatably arranged shafts. The shafts both are provided with pins that are arranged in four comb-like structures on each shaft. During a rotation of the shaft, the interdigitating pin combs pass through each other. This apparatus is rather complicated and expensive.
Another carbon black pelleter disclosed in the prior art comprises a rotatable housing with pins attached to the housing pointing radially inwardly. A shaft may be rotatably or stationary arranged in the housing. This shaft is provided with pins arranged along a helical line. The pins on the housing are arranged in a symmetrical pattern all over the housing. This apparatus has the disadvantage of being also fairly complicated because the attachment of the pins to the housing is cumbersome and servicing of this apparatus is rather difficult. Also the specific arrangement of housing pins and shaft pins, both essentially in helical patterns, prevents strong mechanical action on the carbon black.
Another known carbon black pelleter is provided with a rotatable housing having several pins extending radially inwardly and a shaft having pins extending radially outwardly. The housing pins and the shaft pins are slightly spaced from each other so that the mechanical action is fairly strong. However, the apparatus is still difficult to be built and to be serviced in view of the fact that the pins are attached to the rotatable housing all over the entire interior surface thereof.